Data commit

Task/First-class-functions/D/first-class-functions-1.d

@@ -0,0 +1,9 @@
+void main() {
+    import std.stdio, std.math, std.typetuple, std.functional;
+
+    alias dir = TypeTuple!(sin,  cos,  x => x ^^ 3);
+    alias inv = TypeTuple!(asin, acos, cbrt);
+    // foreach (f, g; staticZip!(dir, inv))
+    foreach (immutable i, f; dir)
+        writefln("%6.3f", compose!(f, inv[i])(0.5));
+}

Task/First-class-functions/D/first-class-functions-2.d

@@ -0,0 +1,18 @@
+void main() {
+    import std.stdio, std.math, std.range;
+
+    static T delegate(S) compose(T, U, S)(in T function(in U) f,
+                                          in U function(in S) g) {
+        return s => f(g(s));
+    }
+
+    immutable sin  = (in real x) pure nothrow => x.sin,
+              asin = (in real x) pure nothrow => x.asin,
+              cos  = (in real x) pure nothrow => x.cos,
+              acos = (in real x) pure nothrow => x.acos,
+              cube = (in real x) pure nothrow => x ^^ 3,
+              cbrt = (in real x) /*pure*/ nothrow => x.cbrt;
+
+    foreach (f, g; [sin, cos, cube].zip([asin, acos, cbrt]))
+        writefln("%6.3f", compose(f, g)(0.5));
+}